About gall stones

40 yr old female, nothing removed from body (yet). Lupus,
fibromyagia, hypothyroid, high Blood pressure 5′2″ 231 lbs.
I had my first gallbladder attack this past Monday evening. I have
been on a clear liquid diet since then and have had my gallbladder
ultra sound today. The tech would only tell me “You have one huge
gallstone and that is all I will say” She told me this because I
told her she would have to give my Dr. some kind of info today
because I can’t stay on this diet through the weekend.
My question is.. if my gallstone or stones are large… what is safe
and unsafe to do. Is a large stone “passable” or can it be broke
down?
My Dr’s. office called and told me to start on the B.R.A.T diet, no
fat at all and to make an appt with a surgeon right away. Also told
me no dairy at all, can folks have non or low fat dairy with this
condition? I am not a huge dairy fan, but I love my low fat yogurt!

Thank you!
Stacie